Comparative Evaluation of Environmental Flow Assessment Techniques: Review of Methods

Abstract

In 1994 the Council of Australian Governments reviewed water resource policy in Australia and agreed to implement a strategic framework to achieve an efficient and sustainable water industry. One of the major recommendations of the review was the introduction of comprehensive systems for water allocations addressing water entitlements, water trading arrangements and the provision of water for the environment.\nThe Agriculture and Resource Management Council of Australia and New Zealand (ARMCANZ) and the Australian and New Zealand Environment and Conservation Council (ANZECC) subsequently commissioned a set of National Principles for the Provision of Water for Ecosystems. The purpose of the national principles is to provide policy direction on how the issue of water for the environment should be addressed in the general context of water allocation decisions. The goal for providing water for the environment is “to sustain and where necessary restore ecological processes and biodiversity of water dependent ecosystems” (ARMCANZ & ANZECC 1996).\nImplementation of the Council of Australian Governments water reforms and national principles has stimulated a wide range of responses from the Australian states and territories (Allan & Lovett 1996). A key issue has been the definition of conceptual frameworks and practical methods for assessing the water requirements of environmental systems. To date, no set of techniques or conceptual framework has proved acceptable to all water agencies or suitable for all circumstances. There is concern that the most suitable methods are not being used universally, with many assessments relying almost entirely on rapid expert panel approaches rather than the best scientific information available (as required under Principle 2, ARMCANZ & ANZECC 1996).\nThe project ‘Comparative Evaluation of Environmental Flow Assessment Techniques’ was commissioned to address these concerns. It is an initiative of the National River Health Program, a cooperative research and development program of Environment Australia and the Land and Water Resources Research and Development Corporation\n(LWRRDC). One of the principal aims of the program is to enhance the management of river flows and water allocation to ensure the sustainability of riverine ecosystems. The program has supported research and development projects throughout Australia, and in 1995 organised a national seminar on ‘Techniques for Environmental Flow Assessment’ held at Cooma, New South Wales. Speakers from Australia, New Zealand, the United States and South Africa reviewed specific techniques and methodologies, and discussed their origins, theoretical basis, applications, advantages and limitations.\nThe Cooma seminar concluded by identifying several priority areas for R&D, including a critical comparative review of the techniques used by water agencies to assess environmental flow requirements in Australia. The project ‘Comparative Evaluation of Environmental Flow Assessment Techniques’ has been funded by Environment Australia, LWRRDC and the National Landcare Program.